Finishing question-washcoat

bases-loaded@juno.com bases-loaded@juno.com
Tue, 5 Oct 1999 06:26:09 -0400


Ric -

Don't know the precise origin of the word "wash" in washcoat, but a
washcoat is merely a "thinned" coat of whatever the material is you're
using (remember whitewash in Tom Sawyer?)  It definitely is NOT sanding
sealer, but you are right in that it is usually used as a means to "seal"
one coat from another - in this case, to seal the color from the grain
filler so as to make it more unlikely you would sand through the filler
to the stain.  Sometimes a thinned or "wash" coat is used to get deeper
penetration into raw wood to show the grain better, too.  In the case of
Tom Sawyer, I guess it was to s-t-r-e-t-c-h the paint...

Sanding sealer is a finish formulated with stearates added to make
sanding it real easy - doesn't gum up or clog sandpaper - makes it wasy
to provide a nice level surface for topcoating.  

Hope this helps...

Mark Potter
bases-loaded@juno.com 

On Tue, 5 Oct 1999 03:47:17 -0500 "Richard Moody" <remoody@easnet.net>
writes:
> 
> 
> ----------
> > From: Charles E Faulk <cfaulk2@juno.com>
> > To: pianotech@ptg.org
> > Subject: Re: Finishing question
> > Date: Monday, October 04, 1999 9:20 PM
> > 
> 
> > The best time to use a paste filler is after staining and after 
> applying
> > a light sealer (or washcoat, as some call it). 
> 
> Wondering where that term came from.  We used to get "wash thinner" 
> which was
> cheaper than laquer thinner, but smelled like it... was used to 
> remove gunky
> stripper from the wood.  I didn't know "washcoat" but wondering if 
> that is what some
> called sanding sealer?---ric
> 


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